COMECOME installed but no Home-screen icon appears
A missing Home-screen shortcut does not necessarily mean installation failed. Check the device's app list and Android's installation result first.
Look in the app list
Search for the installed app using the phone's normal launcher or Settings app list. Some launchers do not automatically place every newly installed app on the Home screen. Read the app identity before opening a similarly named item.
Check the installation result
If the installer was cancelled or reported an error, a completed browser download is not enough. Return to that exact error. If Android reported success, avoid immediately downloading another copy merely because a shortcut is absent.
Separate shortcuts from apps
Removing or missing a launcher shortcut differs from uninstalling the app. Use the device's normal shortcut controls if you want a Home-screen entry. Do not install an unknown launcher or helper just to make an icon appear.
A useful next step
Open the recognised app from the device's app list, then address any sign-in or network issue separately.
Related: Is your COME icon a web shortcut or an installed app?